Seat-support for bicycles.



1-r0.f724,630.v PATENTED APR. 7. 190s.

` C. J. TRA1\M3IIRG` SEAT SUPPORT PoR BIGYGLBS.

APPLICATION FILED SEPT. 1a. 1902, No MODEL. f'

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UNITED 'STATES YPri-*Flinn* OFFICE.

CHARLES J. TRAMBURG, OF MINNEAPOLIS, MINNESOTA.

SEAT-SUPPORT lFon BICYCLES.

SPECIFICATION forming part of Letters Patent No. 724,630, dated April 7, 19 O3.

Application filed September 18, 1902. Serial No. 128,854. (No model.)

To all whom it may concern:

Be it known that I, OHARLESJ. TRAMBURG,

a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Seat-Supports for Bicycles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same. i

My invention has for its objectto provide certain improvements in bicycle-frames.

To the aboveend the invention consists of the novel devices and combinations of devices hereinafter' described, and defined in the claims.

The invention is illustrated in the accom:

panying drawings, wherein like charactersY indicate like parts throughout lthe several views.

Figure 1 is a view in side elevation, showing a portion of a bicycle-frame and a portion of one of the bicycle-wheels and illustrates vmy invention as applied to the said frame. Fig. 2 is a transverse section taken approximately on the line m2 :152 of Fig. 1. Fig. 3 is a vertical section on the line 003 :1:3 of Fig. 2, and Fig. .4 is a transverse section on the line m4 004 ot Fig. 2.

The numeral 1 indicates an ordinary bicycleframe, having, as isV usual, the upright seat-post 2 and crank-shaft hanger or sleeve 3.

The numeral 4 indicates a portion of thev rear wheel ofthe machine, and the numeral 5 indicates a portion of the pedal crank-shaft, the bearings for which are not shown, but would be supported by the crank shaft hanger or sleeve 3 in the ordinary way.

The seat-post is formed in sections. The lower section of the seat-post is anchored to the crank-shaft hanger, and the upper seatpost section is mounted for vertical movements on the lower section, a spring being placed betweenthe said two sections, so that the upper post-section is spring-mounted for movement on the lower section.

The numeral 6 indicates the upper section of the seat-post, which loosely iits and telescopes within the upper end of the frametube 2 and is provided with an ordinary head 7, to which the seat is attached in the ordinary way. The lower section 8 of the seatpostis preferably in the form of a square rod,

vwhich works through a plug 9 in the lower end Vof the post-section 6. The post-section 6 is thus free to move vertically on the rod 8, but isheld against rotation with respect thereto. At its lower end the rod or postsection 8 rests in a squared seat of the yoke 10, which is provided with a vertically-elongated slot 1l, quite-closely fitting the shaft 5 and preventing the said parts 6, 8,'and 10 from rotating. From the yoke 10 depends a short rod or stem 12, which rests in a suitable socket of a supporting bar or head 13, which in turn is anchored to the crank-shaft hanger by a pair of nutted bolts 14 or similar devices.

Within the frame-tube 2 is a collar 15,

pinned or otherwise rigidly secured to the rod vor lower post-section 8.

A seat-supporting spring 16, which surrounds the rod 8, rests upon the said collar 15. As shown, a loose Washer 17 is placed on the rod'8 between the upper end ofthe spring 16 and the plug 9 and the lower end of the upper post-section 6.

The Weight of the rider, which is ofcourse thrown upon the seat-post 6, forces said seatpost downward and compresses the spring 16 against the collar 15. Thus a yielding seatsupport is provided, and the weight of the rider is transmitted through said rod 8, yoke l10, stern'12, head 13, and bolts 14 to the crank-shaft hanger 3.

It will of course be understood that the in- .vention above described is capable of considerable modification without departing from the spirit of my invention.

What I claim, and desire to secure by-Lety ters Patentot the Unit-ed States, is as follows:

` 1. The combination with a bicycle-frame having an upright tube, of a two-part seatpost, the lower section of which passes downA through said tube and is supported from and connected to the crank-shaft hanger below the crank-shaft, and the upper section of which is telescopically movable within said tube, and a spring compressed between said post-sections for yieldingly supporting the seat, substantially as described.

2. The combination with a bicycle-frame having the upright tube 2 and crank-shaft hanger or sleeve 3, of the seat-post sections 6 IOO telescoping into the upper end of said tube 2, the rod 01' section 8 having the collar l5 and tting an angular seat in the lower end of said section 6, the spring 16 compressed between said collar l5 and the lower end of said post-sections 6, the yoke 10 slotted at ll to pass the crank-shaft, the stein 12 depending from said yoke 10, and the bar or head 13 anchored to said crank-shaft hanger 3 by 

